Microsoft Windows and various programs access the registry a few hundred times a second. Therefore a fragmented registry is one of the major reasons why your computer may be so slow. WinUtilities Registry Defrag can significantly speed up your computer by helping you defragment registry, remove gaps, and make it contiguous, smaller and faster to access.
Registry fragmentation is a similar phenomenon as fragmented hard drives, Your Windows registry can become fragmented over time, occupying more space on your hard disk than necessary and decreasing overall performance. Especially when many programs are installed and uninstalled. When programs and other components are removed from the system they can leave behind data inside the registry. After data is deleted from the registry, the space in the file used by that data is kept until it can be re-used by newly added data. If lots of very small bits of data are deleted the registry can become very bloated with 'holes' where no data will fit. This causes the registry to be larger than necessary which in turn means it is spread over more hard drive space and hence slower to access.

WinUtilities Registry Defrag analyzes the structure of your registry and rebuilds it completely from scratch. thus removes any slack space that may be left from previously modified or deleted keys. The registry is defragmented, and any structural errors are corrected. By defragging your registry, it will create a more linear structure maximizing application response times and registry access times, saving memory, and enhanced boot-up times. This can greatly improve system performance and to avoid system crashes and the loss of data.